Directors, Mick Jackson, David Kennard; writer, James Burke
Host James Burke traces the connection between standarization of precious metals used in coins, the great commercial center and library built by Alexander the Great, development of the compass, and creation of the atomic bomb
OcrFerdinand had taken the opportunity of his son's coronation to invite all the princes ships and barons and city representatives Moreover Germany to come here to this rushed out holes for several months of discussions on things like taxation and war and economic policy now they all sat in these benches and Ferdinand of course being Emperor throw. Anyway towards the end of the session for Ferdinand I asked who was here because he was mayor of magnet. If he would do some of the tricks that the bread heard you could do and a good record in this whole obligingly used his to make vacuums in glass. Fear and then amazed the assembled company by showing them that my suffocated in the vacuum. Candles went out in it if you rang a bell and you couldn't hear the bell and all sorts of other goodies. Ferdinand was so taken by the whole thing that when it was over he asked if he could have all the operators and being Emperor Of course he got it tell you didn't have the whole thing written up which is how the rest of Europe got to hear about the vacuum pump. Gricar was a real dabbler and he got very intrigued by one of the thing he read in Gilbert's book The bit about some substances like some attracting sings so to recover quite solidly built itself is rather silly some football on a stick. And he spun it and when he was spinning it he rubbed his hands like this. Now the reason we did that is because he was looking for evidence of what we today would call gravity why I thing stuck to the Earth and didn't fly off into space so when you wrote this experiment up he went into great detail about things like the ball would attract a piece of thread then when the thread was in contact with the ball the thread would attract things. Fortunately he also mentioned something else about which he entirely missed the point he said it's just been a ball and rub it and then take it out and hold it next to your ear you hear a crack and if you do it the dark the ball don't know as I said that was fortunate that I mention it because he's half interested comment kicked off investigation into why the crack in the blow occurred and that turned out to be electricity. You know the fascinating thing about moments like this in history is that they lead to so many places at once. We could for instance go forward from the vacuum pump to the investigation of air to the discovery of oxygen to finding out how the human lungs work to modern respiratory meds. Or we could go. Vacuum pump steam engine locomotives. Or we could go back and pump investigation of gas. Sending electric spark through them to see what would happen the cathode ray tube. Moderator. Or take the globe of the self the globe the fact that the thread when it was attached to remember carried the mysterious force a way down the thread. Lead to people trying to do that deliberately defender forced down wire that in turn led to the telegraph and that in turn led to the telephone. But for our purposes let's take the route that leads to one of modern societies most horrifying inventions. And the next step on that road from this seventeenth century government meetings. Forward into the future. Takes us into the area of the Englishman favorite topic of conversation. The weather. Service office is some connection between directors sparked unlikely so people get all excited about at the serac electricity in general was there gunpowder in cloud was Irish called more electric another car interest centred on the unfortunate church barely spoke Now you mentioned it did tend to get electrocuted rooms monotonous regularity because one of their jobs was to ring the bell during storms. Right thing but taking really serious It's only when they realize doing this little trick. Gunk how the stores kept on doing it. Now this mysterious It wasn't just costing lives it was costing money it was these exposed the thought to public attention to the ideas of the fifteen son of an American so make a post flew his kite in a storm the previous point. Franklin reckoned the key solution was lightning rods that would attract the negative electricity to their positive metal. Six must feel like lightning and it was a disgruntled Mieses finally got the subject white and turned to stone him when this happened. In an attempt to warn the ships of storms the Royal Navy started taking weather reports from as well as readings from their parameters when the first of these collections was put together in eighteen sixty one they had the world's first whether chart of an Atlantic. Pression looking remarkably modern on land the same thing started with stations reporting via the new Telegraph. Now fortunately all this seriousness was tinted with some of the for career insanity of the period by the eagerness with which people now talk to an amazing new invention described just after it came out as infinitely the most extraordinary and magnificent discovery perhaps since creation. Now him I feel it's a bit exaggerated but you can understand why people got the very light headed about it it's one of the symptoms you suffer from when you use it. Going up in a balloon lecture collecting all sorts of doctoring. The you. By the middle of the nineteenth century the balloon enjoyed the same kind of reputation in the backseat of the motor car to the nineteen forty it was rather often used for purposes for which it had not been originally designed I mean Frenchmen in particular would cruise along with girl friends. Dropping and to champagne bottles on the gaping peasants below and returning to Earth to announce their intelligent mind you some of it was all serious I am. They took up parameters and some of his and cats and dogs and geese and ducks and C. Band two hundred lb lady to observe their effect on the weather and vice versa and this intrepid pioneers enjoyed all the privileges of going to high altitude without oxygen a bleeding at the Is and I know was the a vomiting swelling of the head and popping out. Mind you it's possible that I did learn things they never would have if they'd stayed on the ground like the temperature does not decrease steadily as you rise in the sky and no one has the a pressure and some of them state of the day. Justin along enjoying the view. Dropping notes by parachute that never seem to say much other than everything going remarkably well including those who haven't seen again. But. By the late nineteenth century what with only their born anemometers and reports and shipping and stations on the ground using the new electric telegraph you can pick up a copy of your times in the morning and get almost as good a forecast as you can. The only disadvantage to all this high altitude information which by now they regarded as vital Was it sooner or later when you run out of hot air or hydrogen from water and they had to come down but they knew there was some way of playing at high altitude for as long as they live. Which is while story next takes us to a place your imagination of thought of long before it's a place where you can stay at high altitude for as long as you like. The Highlands of Scotland. Thank you Dave. Safe a few a few on a potential the seventy eight hundred eighty six this ancestral home of the bottom of the mountain was a venue for a get together by the cream of unlike the Scottish can kill it is to mark the grand opening of a new weather station on top of the highest pile until I lose them never trust my freshman swell often to the guests and provisions were loaded for the journey to come by numerous factors and killing a them and other members of the I'm pronouncing those gotten from the owner. Ladies and gentlemen thank you so much talk about me for Christ's sake you know I think the commander in chief of the ground was ludicrous. Over a domino effect in a way that also imperfect Victorian public occasions were in any other country in the world that have got the whole thing from the rain stops but this was nineteenth century Scotland and they were bent on serious matters so they could gritted teeth and carefully did Dad duty as the rain filled up their backs. After all it was a home things not being recorded for posterity. Soghoian Thank you know. Oh hold it. So I am thanking the really nice thing about what science did to the Victorian president made the more limited than the same way so the townspeople of fourth William also did this you think about the perception of what I'm getting soaked and waving silly flags of they were supposed to do. Thank you. Nine A.M. the party began their trek up the mountain. Led by a single Piper busking a catchy little Celtic number called the hills I want the facts. Why I've never been able to find out and the rain. Obligingly turned to sleet so everybody could have won the supposed to have when doing one's duty. Suddenly but time. As more and more stations like Ben Nevis with set up and people could sit and look at the weather as it shifted in change they noticed that it made distinct patterns so when good Victorian style they catalog them and then the eighteen nineteen came up with an official international Cloud Atlas which gave clouds the names by which they are known today. And this catalogue of cloud is the next clue in our detective story because clouds caused something strange to happen at Ben Nevis is the from the moment it opened the station observers worked twenty four hours a day. Each shift would send off regular reports on temperature pressure rain and so on and one of the reports they had to file would be about the plows and if you're on the Dawn shift you sometimes see the clouds in the valley. Do something very weird to your shadow. This is called a glory and the strange thing about it is that the colours that appear in the Halo don't appear in the order they do in the rainbow but the other way round. At this point if it took the most extraordinary twist for the very mundane reason that the Ben Nevis Observatory was short of cash and so because of that they used to take on university students during their vacation to act as temporary and paid observers while their own staff as a holiday and it's a temper. Eight hundred ninety four one of those young men was a Cambridge physics graduate called Charles Wilson this is him in much later life. And one morning on Ben Nevis Wilson thought glory and it turned him out so much that he decided to go back to Cambridge and make one for himself to find out how they worked. That's why our detective story brings us here. Because the way Wilson did it and how in the long run what he did came to affect the lives of every man woman and child on earth is illustrated in every museum of any size in the world. This one's the Science Museum in London and Wilson's machines here. Hidden away among the thousands of other clues to mankind's inventive genius. You know considering the amazing thing about the help give birth to Wilson's machine is really a rather an impressive looking object and although you'd expect to find it in the weather section because of the glory business and all that that's not where they put is. Usually the first thing you see is what the machine actually did take a look in here. See those tiny cloud formations. Now Wilson wanted to make himself clouds because he wanted to make himself a glory to work on so he built himself a cloud chamber in eight hundred ninety five this is a later version but the principles the thing here is that a sealed glass container and fitting into the container below it there's a piston inside that cylinder there and underneath the best in the gap and leading from that gap is a tube through this container in which there's a vacuum now if you open the valve on that to the year. Underneath the piston results in here to fill the vacuum that causes the person to be very fast and then this they're up here has more space to fill. Which it does so it gets there are so is there pressure drops and clouds form in here. Now at that time everybody saw clouds formed because the tiny droplets of moisture condensed on little specks of dust in the air but when Wilson clear all the dust out of these machines we still got clouds when I reckon it had to be something about radiation because they were going to have an eight hundred ninety six it took some of the newly discovered X. rays and been them into his cloud chamber and sure enough they made labs but they made them. Tiny streak. Well thought well I've established a relationship between radiation and cloud and that's good enough for me so he dropped his work on the cloud chamber and went happily back to meteorology. And what he didn't realize was that in five that. He had triggered a scientific time. Over the next few years Wilson the magic cloud mega got really turned on by really bad weather and in particular thunderstorms and in very particular situations where things got really spectacularly bad and so he was to be seen. Risking life and limb by poking his instruments as close as possible to a gigantic lightning strikes in order to find out how much power they gave up. And if you're wondering why I am telling you all this in the front end of a wartime B. twenty nine bomber Well one of the reasons is that as a result of Wilson being so interested in lightning war time flying was safer if that's the right word did you. You see when he found out what lighting was doing he probably told a friend of his called Edward Appleton now in one hundred fifty what Apple Thomas tried to do was to find out why when you turned on your numerical machine called Radio what you've got in your ear off and instead of long distance communication. Appleton decided to take a look at what the atmosphere did to radio waves and one hundred twenty four. He finally shot some radio waves up with this guy. Whereupon they promptly banned. Down again to the other three measured how long it took them to bounce back and he said hey listen there is a layer of something one hundred kilometers up there are new because I measured it that reflects radio way. Now all this measurable bit may seem just a touch down to you but it was music to the ears of another weatherman called what what the time was trying to find out if you can use radio to locate storms which of course now we could do he did it by using two radio transmitter so that one would tell you a storm was in that direction so many miles and another would tell you it was in that direction and so you knew where the storm was. OK I hear you say what has this got to do with an obsolete war time bomb. Well all this radio wave super scientific stuff got the military very worked up and in one hundred thirty five the British Air Ministry asked what can what if you could make them a death rate you know destroy enemy planes in the sky. No he said but if radio waves will bounce off storms there also bounce off in a crop so what about me giving you something. It helps you find enemy aircraft in the sky tell you how far away they are and what direction we could call it radio detection and ranging or are a DA R. for short. We can also get to the returning echo from the aircraft to cause the beam of electrons going down a cathode ray tube to make a blip on a screen that had a range skate on it so you could see the air opinion you can see where it was great idea they said and this was the result. The radar that was used during the Second World War. Today because of radar your holidays Jet get to destination safety. Missing the storms and other holidays. And so we come almost to the end of our detective story. You remember how it all started two thousand seven hundred years ago when the touchstone told you you could trust somebody gold and how that got all the merchants racing around the Mediterranean up to Russia now to India and how at the great trading port of Alexandria. The star tables got written but not used by navigators until a new sale and Roger got things moving again in the Middle Ages by which time they knew where they were going. Thanks to the compass which however let them down. So William Gilbert tried to find out why using is magnetic models of the earth that attracted everything and how to record in Reagan got so excited by attraction we try to spring self a bowl and how the silver ball cause bugs and got everybody into atmospheric electricity and the weather and how at the weather station on Ben Nevis Wilson decided to make a cloud chamber then got interested in storms and help to make radar map. I said we were almost at the end of a detective story. Quite. The other read who were on board of B. twenty nine is because one of those bombers also carried the other child of Wilson's cloud chamber. Remember I told you that he'd set off a scientific time bomb when he did that because back in nine hundred eleven he took this photograph of his little cloud streaks and he showed it to a physicist called Ernest Rutherford who said My God you know that is that is a photograph of radiation particles knocking bits of an atom and that means we can see what we're doing when we try to split the atom so Wilson's photograph made it infinitely easier to produce a modern invention that helped us to cure want to. Most deadly disease known to mankind. Or if you choose to wipe out all life on the face of the or that invention was dropped by a B. twenty nine at nine fifteen on a sunny August morning in nine hundred forty five on the air rushing about it with the atomic bomb. Today the nuclear bomb is like a sword of Damocles hanging over. Will it fall again. The. The. And then they run into another problem the problem of steering up until that point you're still at it with a couple of wars one off either side of the stern but by about twelve hundred the ships are so big that those oars just really went feasible anymore which is why they probably picked up an idea from the Chinese that solve the problem there. The stone closed product with a stern Press writer you could handle a ship of almost any size in almost any C. condition so by the thirteenth century the Europeans had all the technology that he sailed the old square sales down for a striker to go anywhere they want to talk they didn't need to use it until fourteen fifty three when Constantinople fell to the Turks and after that it was if you wanted something from the Far East it was either pay the price the Turks wanted for letting it come through their territory or go get it yourself which is just what the Europeans did in the great sixteenth century voyages of discovery. And this was now that the Mariners began to use those star charts prepared in such detail about what you're telling me. Fourteen centuries before. This is the Golden Hind the ship that carried so Francis Drake around the world it's not unlike the earlier caravels failed with the great Portuguese navigators down round the southern tip of Africa and then out across the Atlantic with Columbus in fourteen ninety two so what was it about the ships that meant that you could fail them at will with the ends of the A Well look at the rigging. Now I know it looks like a good few math the roads but if you look carefully with the the old square say oh they're on the front. Marked and some of the ships had one some two sometimes even three masks carrying the square sail. But on the back and there was a mass with the familiar triangle shape of the law teens and it was this mixture of sale that allowed you to cross an ocean. Anytime you want to look here in Spain. Here's the northern part of Africa and over here there's America in the Gulf and then South America now in the area here off the coast you get winds going in all sorts of directions very variable so you use the lucky and sail to talk yourself into a position where the study north easterly trade winds which you can pick up on this player sales will take you straight across the Atlantic when you want to come home we do the same thing the other way round. Exactly the variable winds until you pick up the westerlies you put up the square sails and the westerlies bring you all the way home. Most of the that they use at the time I made in my Yorker and by the fourteenth century they weren't turning out. Portal and charts and updating them as explorers going back with more information now the charge contained only want to say they needed to know. No in land detail at all just details of the coastline the names of the harbors and these lines showing the directions of the major and minor winds along which is still a chance for very precise and because the aim of the people using the profit they were also very secret. But the thing that really gave Europe the world on a clicked was that the first reference we have to reduce by an English monk around about twelve hundred it probably came from China via the Arabs to Europe and early on they would have use it like this. And the magnetized needle stuck through the straw would point north and then around about thirteen hundred somebody probably of the maritime Republic of a mouse clicks south of Naples Italy idea of mounting the logs of putting a card on it and on the card or putting the wind directions and putting the whole thing in a box. The effect of the compass was electric in more ways than one it will see. Firstly it meant that you could go out sailing under cloudy skies because you no longer needed the stars of the sun to steer by and the immediate effect of that was to double the number of voices because now you could say off in the winter so so can spices from India and gold and silver from America began to porn really York. And it wasn't until enough men had sailed to enough places that they realized that the faithful compass was lying. It was true north the north of the pole star and that was the magnetic north and depending where on earth you were that varied and for a great mercantile empire like England that was very bad news. I suppose Shakespeare and the prevalence of done more than anybody else to give us our Technicolor view Elizabeth an exit. Starring the queen herself as a kind of trust back there in Perth. Fact is about all she had time for was bookkeeping when she took the place over in fifteen fifty eight it was a national disaster when the money was worthless there was no money that would place the cities were packed and stick it. Elizabeth appealed to the decent English middle class with their hope he does offer prestige power funny game. Tonight. Anybody who wanted to be anybody was on the net and none more than that famous bunch of privateering seagulls led by trade. Rally and hope to sail the Atlantic looking for new American trade opportunities for England. Setting up colonies knocking off punish Guardian and doing it all with a kind of got to disregard for convention that we described today as a criminal. I knew. The privateers would bring back everything they could lay their hands on even estimate. Somewhere in among the hustle and bustle and talk of adventure during the Great speech stays at places like company called the must always have been coming home saying hey this is you'll never guess what happened to my compass in it that's good. News it is. Good. To. Put food on the one. Who does. Now the reason why all those pushy ambitious high living upper middle class Elizabethans gave a data about which way a compass needle pointed was because the West Front. Tested profits to be had in overseas trade and if you'll need to let it down and he went off course with a pretty good chance you wouldn't get home with all the lovely money to the problem of the needle was really quite simple. It didn't always point in the same direction. And people have been saying that since fourteen ninety two when Columbus on the way across to America got to about here and panicked because suddenly he realized that his needle wasn't pointing at the North off. And then in fifteen eighty went to Francis Drake got back from his around the world trip was enough gold and jewels. Pinched from one of the Spanish ship on its way home from a route to give his back as four thousand five hundred percent profit. Well it was obviously time to do something about it because if his needle had let him down look what they would have all lost. So in fifteen eighty one a compass make a cold robot Norman decided to look into the matter and he did this. On a so nothing happening which was very odd I mean for a start he said if a needle is supposed to be attracted to the north. Why doesn't it move to the north instead of sitting in the middle of the bowl doing nothing. Well Newman's remarks attracted the interest of a certain William Gilbert's wasn't a failure. Wasn't much and I don't fact he was a well heeled Society Dr eventually to become a physician to the queen. Now like most of the medics at the time. Gil but knew a bit about negatives him because his profession was very much into metal. They had recently stopped an epidemic of syphilis by treating it with Macquarie in the form of mystery Cox not this red powder and Mike nitpick middle was recommended for treating people with because it was supposed to bring the disease out of them. So over a period of about eighteen years ago but went home at the end of every day and fiddled around with natural magnets made of loadstone and since the name of the game is to find out why the compass needle varied as it went around the earth he made his little magnets in the form of if and when he got plenty of them ready he started experiments and brought anything he could think of in contact with these magnets. Including of course a compass needle which behaved exactly as he said it should. Wherever he moved it the needle pointed at the north pole of his tiny magnet so we reckon that the Earth itself had to be a giant magnet with the magnetic north pole and it was that the compass pointed out not the North Star. What's more he said if you leave one of these things alone. It turns once in a day and therefore they must do exactly the same thing and he said if there is a magnet that's why what goes up must come down because it's attractive in sixteen hundred down everything you discovered the vast book and in doing so he set in motion a train of events that would one day lead to one of the most frightening but of technology in the modern world. It called his book magnetic about the magnets. Book was practically an overnight success in Europe I mean first thought he was writing in Latin so we didn't have any translation problems most of the intellectuals around use let in to work with and then look what he was saying that the Earth is a giant magnets putting in space surrounded by the vacuum of interplanetary space and out there in that vacuum there are thousands and millions of stars and planets. Anything isn't Sixteen hundred No wonder everybody went bananas about it and the reason the detective story takes us next to this small town on the Danube in southern Germany is because of one man who got very excited by what go but had said his name was autos and sixteen fifty three he was here in Reagan's bug commanded by the Emperor to attend the coronation of is some combination was the occasion for a great imperial shindig in the town with dancing and drinking and singing and generally wrapping it up. Robber like the annual Reagan broke brawl going on here today. The. In Reagan's bugs some of them all meaningful traditions haven't changed a bit in Hungary did hear. The it. Was sober citizens a break and Doug claimed that it was here in sixteen fifty three that auto gear Rekha did something quite amazing as a result of reading what Gilbert had said about the nothing with an interplanetary space here in Reagan's but they say he took a hollow boom and made of two hemispheres that fitted together harnessed both is that each side of the boat and however hard they pulled the ball refused to come apart. Although the two cards were not held together by any kind of joint What kept them United was a mysterious force so powerful that policy couldn't break. They say that after the experiment was over. Garrick I went on to astound the onlookers by opening a tiny hole in the boat at which point it fell apart with the trick of it's not. Now whether or not that actually happened in Reagan's Berg is neither here nor there the fact is it caused a tremendous all over Europe because the mysterious force holding those numbers we have together is what Gilbert had been be writing about in sixteen hundred and what Ian sixteen fifty four had only just been discovered the vacuum put inside there's a mysterious by the newly invented vacuum pump invented by auto good Wicca or rather a ducted buyout of director because what he did was adopted one of the you know that it's it's what you have to have handy if most of the buildings made of wood it's a fire extinguisher. Big. And. Director adapted it to suck air instead of water and it was a very big hit with him. Ferdinand the third Holy Roman Emperor. All right. I would say it was a pretty safe bet that the one magic wish most people would like to be ground would be to be able to see into the future and think what it would me. Backing the right. Now because we have to guess about tomorrow and we have to act on that gas and it's never been any different and that's why following the trail from the pop up to the emergence of the modern technology that surrounds us in our daily lives and affects of lives is rather like a detective story because it no time in the pot as anybody who had anything to do with the business of inventing or changing ever know what the full effects of his actions would be. He just went ahead and did what he did. Prison reasons likely to. That's how change comes about. And it's like a detective story because if you follow the trail from the pop up to a modern man made object the story is full of stuff and twists also lose them I guess work and you never know where the story is heading. Until the very last minute. This detective story starts in the eastern Mediterranean about two thousand five hundred years ago and it starts for the subject dear to most people's money and because that's the way things go it is it will end as well all these programs with something totally different in this case a modern day invention that affects the life of every man woman and child on her. Take a self back then to a time in the Mediterranean was practically empty when the ancient Greeks had only just turned up and together with the finish and then the Egyptians were about all the was living in cities we would call villages when if you wanted to trade with somebody it was a case of the Meet me in the market square and I'll give you my vegetables if you give me your club you bastard. Because there was no such thing as cash. And the reason we've come looking for clues in this particular city on the Mediterranean has to do with how cash was invented and what happened as a result the way it happened. Shows how to change comes as much as anything by accident. Sometime around seven hundred B.C. in a place called Lydia what is now modern Turkey there was a river that washed go down from the local mountains and the local people used to pan it and melted down or religious objects. Jewelry that kind of stuff and then in the river bed somebody came across this. It's called a touchstone and if you rub gold on to list you get a streak but it's the rub gold mixed with silver or something else just you've got a different kind of streak she would only if that streak is pure gold and somebody trying to offload garbage onto your well you take what he calls golden You rub it on the touchstone you could see immediately that what he says of gold isn't up to your standards. Well the Lilian's went immediately into the business of standardizing their precious metals and over the next three hundred years or so all over the eastern Mediterranean and in Precious The Hobbit spread of accepting metal instead of good as payment. Because now you could trust the value of the metal after that point in any state or empire that had a minute making coins the need of money. Really stimulate trade. By the time Alexander the Great was running everything from India to into his coinage was accepted everywhere and his world was like one giant marketplace twenty three hundred thirty one B.C. he decided to build a big commercial center to handle the flood of good crisscrossing example this with the name Dr Alexander you could do two things to get really rich and get a cup of the best education in the work. You see. Alexandria had a library. And what a library. It's opening hours went on for maybe a thousand years at its height it had more than a half a million bucks and that was it I mean if it wasn't here it wasn't worth knowing about it. And then in the end somebody burned every single book. Nobody knows fanatical Christians fanatical Arabs to take a pic. Religion at work. Left nothing. Well almost nothing. Because the next clue in this particular historical detective story takes us down a whole. Of course this was no ordinary hole it led down to a kind of extra backup library and since it wasn't above ground to be destroyed. It's still here. It's a real honeycomb of time on down here. Lika a literary rabbit warren. Now all the books were stored in catalog just like we do today according to subject heading and placed images like these of course being a big sea port the main interest was in or tickle things like maps geography blocks aids to navigation that sort of thing and they were all written in ink on for pirates made from slivers of read stuck slap together and they came out like this in the form of scrolls now they've got these girls either because local scholars wrote them or go further rather crafty law if you came to Alexandria on a boat and you owned a book you had to lend it to the library to be copied and sometimes the copies were so good the owners went off with a fake and the hybrid kept the original this is a copy of one of the lab is best selling author Claudius Ptolemy title all you ever wanted to know about calculation. Thirteen volumes of the astronomy that was known at the time. One of the volumes of The Star catalogue containing one thousand and twenty two stars look. Here's the name of the star is the Zodiac sign it's in German on such a terrorist. Here's where it is in that don't yet it northern or southern hemisphere. How many degrees east or west on the sky is it and how bright is it. Ptolemy did the score to about one hundred fifty eight deep and they're one of the great examples of an idea head of its time because one of the ways this was to be used by satan to have enough the world in a way you're going to see happening later in this program wasn't going to come for over fourteen hundred here. And as for the sailors pouring in and out of Alexandria in telomeres time well they just weren't interested in chance of this guy. Some failing astronomers might have used them in order to find out that position because you see if the tables told you that in a certain time a star should be in that position in the sky and you actually saw him in that position you could work backwards so to speak to find out what position you have to be in order to see it about different angle. But the say this back to the map and they went. Because from the very beginning they do huge ships with the kind of sales that makes it hard to get into serious navigational problems a square thing but only take shoes the way the wind blowing which is what they did right through the Roman period with bigger ships and richer Coggins until suddenly around seven hundred A.D.. The newly arrived Arab pirates gave one simple order open your wallet and repeat after me. Don't go so. You didn't today took it anyway. It became clear to even the dumbest mentions that the quickest way to lose a fortune was to put it all in one big fat cargo ship to the Arabs could take the last Everybody started spreading the risk in a small issue left to be plundered in one go. That switch to the use of smaller ships brought into general use something that would help the Europeans colonise America centuries later. The very earliest picture we have of it comes from a manuscript written in the ninth century in Byzantium it was a sale the kind of sale it had previously Any been used on smaller ships and the kind of say that you can find on a modern Arab down like this one today. Look at the shape. It's triangular Now that is a Latina. Sale and what you could do was a lot in there was something you could never of done with the old Roman square sail. But suppose the wind is coming in this direction with the last scene sale you can say I'm in a direction right up until they're almost selling against the wind. On either side of it on a long journey they would go like they went from this side and they would track and take their word from this side and they would check again like the wind again from this site. Mind you it wasn't something enjoy doing too much I mean look at it involved. Apart from the fact that with a ton of tackles you needed and a lot more crew to handle the worst bit came when the ship was just about to cross the with at this point you had to lift the Stockton right over the top of them out and doing that in rough weather was no Still it was a lot better today in the wrong direction. No if you're not a sailing for you may not be turned on by the Latin fail but as you'll see it means a great deal more to you than you might think the Although it was nice to be able to win back everywhere. Failing like that was the only thing that happened because of the tempest triangle. The letting sale permitted one other thing with it to you could leave port pretty well when you wanted to without having to wait for when that was going in the same direction you are now that meant he would leave for more often that meant it was more cargo on the move more trade more prosperity. It's probable that the Arabs introduced a Latin sail into Western Europe. Just about in time to play a major role in the recovery of the European economy after the chaos and confusion of the so-called dark ages. However by about twelve hundred there was so much bulk cargo like grain or crusade is going to the Holy Land so much bulk cargo on the move that the ship has got very much bigger and then they run into another problem the problem of steering is he up until that point you steer it with a couple of quarters one off either side of the stern but by about twelve hundred the ships are so big that those always just really want feasible anymore which is why they probably picked up an idea from the Chinese. That solve the problem there is. The stone cold product with a stern Press writer you could handle a ship of almost any size in almost any C. condition so by the thirteenth century the Europeans had all the technology the that he's failed the old square sail the stone for a striker to go anywhere they wanted to they didn't need to use it until fourteen fifty three when Constantinople fell to the Turks and after that it was if you wanted something from the Far East it was either pay the price the Turks wanted for letting it come through their territory or go get it yourself which is just what the Europeans did in the great sixteenth century voyages of discovery. And this was now that the Mariners began to use those star charts prepared in such detail I thought the autonomy fourteen centuries before. This is the Golden Hind the ship that carried so Francis Drake around the world it's not unlike the earlier care of own sailed with a great Portuguese navigators down round the southern tip of Africa and then out across the Atlantic with Columbus in fourteen ninety two so what was it about the ships that meant that you could fail them at will with the ends of the OR Well look at the rigging. Now I know it looks like a good math the roads but if you look carefully with video with square fail there on the front. Mark of some of the ships had won some to sometimes even remarks carrying the square sail. But on the back and there was a math with the familia triangle shape of the law teens and it was this mixture of sale that allowed you to cross an ocean.